Over the last decade, millions of public dollars intended for wildlife preservation areas were spent off the books on state office needs, equipment and building construction, officials say.

SACRAMENTO — Over the last decade, millions of public dollars intended for wildlife preservation areas were spent off the books on state office needs, equipment and building construction, among other items, officials said Thursday.

Last year alone, at least $1.7 million was diverted from California's Wildlife Restoration Fund to pay for office operations, routine bills and gift cards for official use, according to Mike Taugher, a spokesman for the Department of Fish and Wildlife. The irregularities were found in an internal department investigation.

The discrepancies follow a string of controversies over spending and accounting practices in other divisions including the Recreation and Parks Department and state Department of Forestry and Fire Protection. Taugher said it was not clear how much money had been misused in the fish and wildlife department and that the probe was continuing.

"So far," he said, "we have found very little, if anything, to indicate anybody was motivated by personal gain.''

The Department of Fish and Wildlife manages more than 1 million acres of habitat. About 130,000 of its acres are leased to farmers for grazing and other agricultural uses to help defray the cost of maintaining the areas.

Payments for 50 of the more than 100 leases in effect last year did not go into the restoration fund, the investigation found. Instead, department supervisors directed tenants to put the payments into accounts that were not part of the state treasury and were tapped for various expenses.

In December, a report by the state auditor found $5,000 that had been put on Home Depot gift cards and could not be accounted for.

In a letter to his staff that was released Thursday, department Director Charlton H. Bonham wrote: "Through our own internal review, I learned that the lease irregularity examined by the state auditor was not unique." He said there would be policy changes to prevent similar problems in the future.

He said in a separate letter to the auditor, "I take these allegations very seriously."

Taugher declined to say whether anyone had been fired or suspended for mishandling the department's money but noted that Bonham has made personnel changes in the agency since taking it over in September 2011.

Legislators briefed by the department Thursday voiced concern about the practices the latest investigation revealed.

"Unfortunately, this is yet another example of people working independently without proper checks and balances," said Assemblyman Adam C. Gray (D-Merced), chairman of the Joint Legislative Audit Committee.